Systems and methods herein generally relate to moisture sensors, and more particularly to moisture sensors that change shape based on different levels of moisture.
Many packaged goods are sensitive to the presence of humidity, and such goods may be prone to degradation or spoilage in the presence of excess humidity. Frequently packages of silica gel are included in packaging in hope that excessive moisture can be absorbed. Such packets are generally small and do not contain indicating means, therefore do not provide an easy way to tell if the humidity was higher than that considered allowable.
A conventional hygrometer measures relative humidity levels, and often includes a pointer moving over a dial. Some conventional micrometers connect the pointer to a coil made from multiple materials that have different expansion/contraction rates based on different humidity levels, which causes the coil to curl and uncurl with different moisture levels, thereby moving the pointer on the hygrometer according to the moisture level.
Additional devices can change electrical conductivity based on different levels of humidity (where the electrical connective nature of water changes the measured electrical resistance) or can change color when excessive amounts of humidity are encountered (based upon chemical reactions). However, all such devices require complex metalworking, chemical composition, electrical structures, etc., which drives the price of such devices to the point that they cannot economically be used in all situations where the moisture/humidity needs to be monitored.